Question: Which of the following numbers is a factor of 192? ${3,7,10,13,14}$
By definition, a factor of a number will divide evenly into that number. We can start by dividing $192$ by each of our answer choices. $192 \div 3 = 64$ $192 \div 7 = 27\text{ R }3$ $192 \div 10 = 19\text{ R }2$ $192 \div 13 = 14\text{ R }10$ $192 \div 14 = 13\text{ R }10$ The only answer choice that divides into $192$ with no remainder is $3$ $ 64$ $3$ $192$ We can check our answer by looking at the prime factorization of both numbers. Notice that the prime factors of $3$ are contained within the prime factors of $192$ $192 = 2\times2\times2\times2\times2\times2\times3 3 = 3$ Therefore the only factor of $192$ out of our choices is $3$. We can say that $192$ is divisible by $3$.